Generation of human peripheral blood stable E-rosette-forming T cells by interleukin 1

Abstract

The ability to form 37°C stable rosettes with sheep red blood cells is a property of activated human peripheral blood T lymphocytes. The frequency of stable E-rosette-forming T cells is markedly increased in a number of disease states. In the present study, we have investigated the role of interleukin 1, a key mediator of macrophage-dependent T-cell activation, in the generation of stable E-rosette-forming human T cells. When human T cells were incubated with either normal human monocyte or murine macrophage tumor cell line-derived interleukin 1 (IL 1), the frequency of stable E-rosette-forming T cells increased dramatically. This effect of IL 1 was both concentration and time dependent. Enhanced stable E-rosette-forming activity was detected within 6 hr after addition of IL 1 and reached a plateau after 60–70 hr. The stimulatory effect of IL 1 was markedly inhibited by sodium azide. Mild trypsin treatment of T lymphocytes revealed that the effect of IL 1 on rosette formation was dependent on the appearance of new cell surface receptors for the sheep red blood cells. Our results support the hypothesis that the macrophage, via the release of IL 1, may play a pivotal role in the generation of stable E-rosette-forming T cells in a number of disease states. The effect of IL 1 on the appearance of stable E-rosette receptors on T lymphocytes is consistent with its general role in increasing the functional activity of different cell types involved in immune and inflammatory responses.